The dollar rose against  major peers as investors sought the safest assets before an Italian vote on austerity plans and European bank stress-test results.

The U.S. currency appreciated most against higher-yielding currencies after Federal Reserve Chairman Ben S. Bernanke tempered expectations the central bank will resume buying bonds in a testimony to the Senate Banking Committee yesterday. The greenback sank earlier after Standard & Poor’s became the second rating company this week to say it may cut the U.S.’s top credit grade. Switzerland’s franc traded near a record high against the euro after a flare-up in the sovereign-debt crisis this week threatened to engulf Italy.

“There’s a flight to quality, if you can call the dollar quality, that’s clearly the issue here,” said Carl Hammer, chief foreign-exchange strategist at Stockholm-based SEB AG. “There are huge risks out there.”